The NHC uses what is called the Saffir-Simpson Hurricane Wind Scale to measure tropical cyclones that become stronger than a tropical depression or tropical storm. According to the Associated Press, Robert Simpson designed the scale to mirror the Richter scale that measures earthquakes.

In an interview, Simpson said there is no reason for a Category 6 on his scale because it was created to measure damage to man-made structures.

“When you get up into winds in excess of 155 mph, you have enough damage if that extreme wind sustains itself for as much as six seconds on a building it's going to cause rupturing damages that are serious no matter how well it's engineered.”